[PATCH 4.14 085/164] KVM: arm/arm64: vgic: Preserve the revious read from the pending table

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Marc Zyngier <marc.zyngier@xxxxxxx>

commit ddb4b0102cb9cdd2398d98b3e1e024e08a2f4239 upstream.

The current pending table parsing code assumes that we keep the
previous read of the pending bits, but keep that variable in
the current block, making sure it is discarded on each loop.

We end-up using whatever is on the stack. Who knows, it might
just be the right thing...

Fixes: 280771252c1ba ("KVM: arm64: vgic-v3: KVM_DEV_ARM_VGIC_SAVE_PENDING_TABLES")
Reported-by: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
Reviewed-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 virt/kvm/arm/vgic/vgic-v3.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -324,13 +324,13 @@ int vgic_v3_save_pending_tables(struct k
 	int last_byte_offset = -1;
 	struct vgic_irq *irq;
 	int ret;
+	u8 val;
 
 	list_for_each_entry(irq, &dist->lpi_list_head, lpi_list) {
 		int byte_offset, bit_nr;
 		struct kvm_vcpu *vcpu;
 		gpa_t pendbase, ptr;
 		bool stored;
-		u8 val;
 
 		vcpu = irq->target_vcpu;
 		if (!vcpu)